Relay.



Racom.

RELAY.

APYLIUAT-ION FILED MAB.20, 1909.

Patented July 27, 1909.

INVENTUR: man ELEUREY.

, UNITED 'STATES' PATENT oEEieE.. FEED E. oo REv,V oF scEENEcTADY, NEW Yon-K, Essienon ToeENEnAL ELECTRIC coMPANY,

' .A eoaroRATioN on NEW Yoan.

RELAY.

'raeestedauiy a7, 190e.

Application filed March 20, 1909. Serial No. 484,668.

To 'all whom it may concern:

Be it known that I, FRED B. Conni', a citizen of the' 'United States, residing at Schenectady, county of Schenectady, State of New York, have invented certain new and useful'lmprovements in Relays, of which the following is a specification.

` My invention relates to relays, and particularly' to relays for use in railway sig-v which,

Because of danger from lightninfr, if metallic contacts were employed, mivht fuse the contacts together so as to give fase clear indications, it has been customary in relays for railway signaling to employ nonvfusible material in the form of carbon blocks for the contacts.

A carbon contact has the disadvantage of increasing its resistance with-use, apparently because of the wearing away of the softer portions of the carbon.

The object of my invention is to provide a novel contact construction for a'rela'y, whereby the usual carbon blocks, forming a nonfusible contact, may be employed without .producing the usual increased resistance with use.

'My invention consists 1n providing a nonfusible contact in the form of a carbon block,

a metallic contact piece normally resting against the surface of the block, and a metallic contact relatively movable into and out of engagement with the contact piece, the contact piece beingadapted, if it becomes fused te the metallic contact, to be moved away from the non-fusible block. With this construction the circuit is normally closed and opened between tlie metallic Contact piece and the metallic contact. There is, thus, little wear to increase the resistance between the contact piece and the non-fusible contact. with which it normally remains in engagement. Should the contact piece, however, liecome fused to the metalliccontact, it wouldbe lifted away from the non-fusible contact, so as to open the circuit and to prevent a false clear indication.

My invention will best be understood by reference to the accompanying drawing, in whiclil y Figure l shows `a relay with contacts arranged in accordancewith my uvention; Fig. 2 shows a modified contact arrangement, and Figs. 3 to 5 show enlarged detail views of the contact of, Fig. 1.

Tn Fig. 1, A renresentsa terminal stud or binding post which carries at its lower end a carbon block B, which forms a non-fusible contact. The end of the stud A may be split and the carbon block B clamped between the split portions by a screw a, as is best shown in Figs. 4.- and 5; C represents a metallic contact piece which normally rests freely on the carbn block B.. This contact piece is shaped like a tack with a central shaft eX- tendinJ into a .recess in the carbon block B. Suitab e insulation, such as a glass tube b is placed in the recess to insulate the shank from the Walls of the recess. The piece C is referabl'y of silver, since this metal makes a ow resistance contact with carbon. A thin platinum disk c may be soldered to the top of this piece to receive the movable contact, since platinum oxidizes less freel than silver, and is, consequently, less a feeted by the are caused by opening the circuit. which is preferably of platinum, and is carried by the pivoted armature E of the electroinagnet F.

During the normal operation of the relay D represents' the movable contactthe piece C remains in engagement with the ever, the contact D should become fused to the contact piece C, the contact piece would be lifted out of engagement with the carbon block so 'as to open the ncircuit upon thefdeenergization of the rela Fig. 2 shows a modified arrangement of the contacts. D is .movedupward to engage the stationary contact and in place of a Contact piece resting by its own weight on the carbon block, a contact piece in the shape of a light'spring C1 rests against the lower surface of the carbon block B, being normally held in-en.

gagement with the contact plugby its own spring pressure. Upon fusion between the spring Cl' and the movable Contact D, the spring would be drawn away from the carbon block, so as to open the circuit upon the denergization of the relay.

In Fig. 2 the movable contact.

l do not desire to limit myself to the plartisular construction and arrangement oi parts here shown, but aim in the appencied claims to cover all modifications which are Within the scope of my invention.

What I claim as new and desire `to secure by Letters Patent of the United States, is,-

1. In a relay, a non-fusible Contact block, a metallic contact. piece normally resting. against the surface of the block in electric Contact therewith, and a metallic contact relativelyY movable into and out of engagement with said contact piece, said contact piece being adapted to be moved by said metallic contact, upon fusion therewith, away from the non-fusible Contact block.

2. In a lrelay, a non-fusible Contact block, a metallic contact piece normally vresting freely against the surface'of theblock in electric Contact therewith, said Contact block and contact piece bein@ shaped to prevent lateral displacement o? the Contact, piece,

and a metallic Contact relatively movable into and out cf enagement with said contact piece.

In ay relay, a non-fusible Contact nlocli,

,a metallic contact piece normally testing' freely onthe surface oi' saicl block in electric Contact therewith, anni a metallic con-- tact relatively movable into and ont of engagement Wit-h said centact piece.

4t. In a ijelay, a non-fusible contact block, a metallic contact piece normally resting 'freely on the surface of said block in electric contact therewith and having a shank extendin into a recess in said block, said shank being insulated from 'the Walls of said recess, and a metallic cont ci'Y relatively movable into and out of engagement with said Contact piec In Witness whereof, l have hereunto my hand this 18th clay ci March., i909.

f @LED B. CGREY. Witnesses:

MARGARET E. ille-mung HELEN Ommen. 

